Vacuum operated electrical switch or the like



Feb. 1, 1966 D. c. PRIDHAM, JR. ETAL 3,233,059

VACUUM OPERATED ELECTRICAL SWITCH OR THE LIKE 3 Sheets-Sheet 1 Filed Aug. 22, 1962 LINE l LINE 2 INVENTOR PRIDHAM,JR

. PALMER MORRIS ATTORNEY Feb. 1, 1966 D. c. PRIDHAM, JR., ETAL 3,233,059

VACUUM OPERATED ELECTRICAL SWITCH OR THE LIKE 5 Sheets-Sheet 2 Filed Aug. 22, 1962 INVENTOR. DONALD c. PRIDHAM,JR,; REED A. PALMER LOUIS P. MORRIS ATTORNEY 5 Sheets-Sheet 3 D. C. PRIDHAM, JR. ETAL VACUUM OPERATED ELECTRICAL SWITCH OR THE LIKE Feb. 1, 1966 Filed Aug. 22-, 1962 INVENTOR. C. PRIDHAM, JR. A. PALMER LOUIS P. MORRIS rt... 4. W

ATTORNEY DONALD REED BY United States Patent 3,233,059 VACUUM OPERATED ELECTRICAL SWITCH OR THE LIKE Donald C. Pridham, Jr., Orange, Reed A. Palmer, Los Alamitos, and Louis P. Morris, Garden Grove, Calif., assignors to Robertshaw Controls Company, Richmond,

Va., a corporation of Delaware Filed Aug. 22, 1962. Ser. No. 218,693 7 Claims. (Cl. 200-83) This invention relates to pressure operated electrical switches and has for its primary object to provide a switch having a minimum number of parts.

In some commercial appliances, such :as in domestic washing machines, dishwashers, driers and other operating devices which require control elements, a concerted effort is constantly being made to eliminate the number of parts for each operating component. It is therefore desirable to provide components in which each part performs a multitude of functions, thus eliminating the number of parts :and reduce the total cost of the component.

Currently, the state of the art switches perform rather simple functions but require a multitude of parts to operate these functions. The present invention is operable on a very few parts and functions best under the influence of a Vacuum source or a pressure source to actuate the switch elements. While the vacuum operated switches of this invention can be utilized for any desired purpose, it is found that the subject invention is particularly useful in connection with vacuum program controls and the like. It is particularly advantageous for the switches used in this sort of system to be operable on rather small variations in pressure to operate effectively by a relatively small vacuum pump.

It is a further obiect, of the invention, to provide a switch in which the foregoing functional characteristics are obtained by a simple compact and sturdy switch unit in which the components are held to a minimum number and may be quickly and easily assembled at a low manufacturing cost.

The foregoing objects are accomplished, according to the present teaching, by the provision of a switch employing :a pressure sensitive unit in the form of a pair of diaphragms joined together to form a housing having two or more electrical contacts therein. The relative position of the contact elements for the switch may be varied in position to effect the particular variety of switching being desired.

Other objects of this invention will appear in the following description and appended claims, reference being to the accompanying drawings forming a part of the specification wherein like reference characters designate a corresponding parts in the several views.

FIGURE 1 is a schematic view illustrating various embodiments of the switches of the present invention used in combination with a vacuum program control system.

FIGURE 2 is a fragmentary side view of the structure illustrated in FIGURE 1.

FIGURE 3 is a plan view of the structure illustrated in FIGURE 1.

FIGURE 4 is a side elevation of one embodiment of the present invention.

FIGURE 5 is a sectional view looking into the open side of the switch in the direction of arrows 5--5 of FIGURE 4.

FIGURE 6 is a sectional view through the switch and its associated mechanism of another embodiment of the present invention.

FIGURE 7 is a cross sectional view of yet another embodiment of the present invention and associated mechanism.

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FIGURE 8 is a sectional view through the switch and associated mechanism of an alternate construction of the embodiment illustrated in FIGURE 7.

FIGURE 9 is a sectional view through the switch and its associated mechanism of another embodiment of the present invention best suited as a normally closed switch.

FIGURE 10 is a sectional view through the switch and its associated mechanism of another embodiment of the present invention best suited as a normally closed switch.

FIGURE 11 is a sectional view through the switch and its associated mechanism of another embodiment of the present invention best suited as a normally closed switch.

FIGURE 12 is a sectional view through the switch and its associated mechanism of yet another embodiment of the present invention as used for a normally closed switch.

FIGURE 13 is a sectional view through a switch and its associated mechanism for an alternative arrangement for a normally closed switch according to the present invention.

FIGURE 14 is a sectional view through a switch and its associated mechanism of yet another embodiment of the present invention.

FIGURE 15 is a sectional view looking into the open side of the switch in the direction of arrows 1515 of the switch illustrated in FIGURE 14.

Before explaining the present invention in detail, it is to be understood that the invention is not limited in its application to the details of construction and arrangement of parts illustrated in the accompanying drawings, since the invention is capable of other embodiments and being carried out in various ways. Also it is to be understood that the phraseology or terminology employed herein is for the purpose of description and not of limitation.

Referring now to FIGURES l, 2, and 3, an improved system using the present invention is generally indicated by the reference numeral 20 and comprises a reading head or block 22 having an upper surface 24 interrupted by plurality of switch passages 26, 28, 30 and 32 respectively interconnected to conduits 34, 36, 38, and 40 leading to a vacuum operated switch 42, 44, and 46 constructed according to the present invention.

The reading surface 24 of the reading head 22 is also interrupted by a plurality of vacuum passages 48 respectively disposed in spaced aligned alternating relation with the switch passages 26-32. The suction or vacuum passages 43 being interconnected to a common suction manifold passage 50 interconnected to the inlet side of a relatively small vacuum pump 52 by a conduit 54.

The vacuum pump 52 can be operated by a suitable electric motor 56 as desired.

A thin flexible sheet or card 58 is adapted to pass over the reading surface 24 of the reading head 22 in any suitable manner and has a plurality of indentations or blisters 59 formed therein which are adapted to successively and in any desired pattern span the spacing between a suction passage 48 and one of the switch passages 26-32. This arrangement connects the vacuum source with one of the interior of the switches 42-46 to close the contacts thereof and operate suitable apparatus. As illustrates this condition. Switch 44 is shown in the closed source.

When it is desired to break the vacuum in one of the switch constructions, the program sheet 58 has apertures 60 formed therein which are adapted to pass over the switch passages in any desired relations so that air can be drawn into particular switch to break the flow of electrical current therethrough.

33 and mounted on the diaphragm. The switch contacts 65, 66 are normally being held out of electrical contact when the closure is at atmospheric pressure and switch 42 illustrates this condition. Switch 44 is shown in the closed position with the contacts engaged.

The switch contact 66 of the switch 4-2 is interconnected to Line 1 of a suitable power source by a terminal 63. The switch contact 65 having a terminal 69 is inter connected to Line 2 of the electrical power source by a lead. An electrically operated device 70, disposed in lead 71, is actuated when the switch contacts 65 and 66 engage each other. Lines 1 and 2 are connected to a power source (not shown).

In operation, the program sheet 58 has a blister 59 bridging the gap between the passages 28 and 43 so that air can be expelled from the closure 64 to cause the diaphragms 62, 63 to be flexed toward each other, carrying the switch contacts 65, 66 into engagement. This engagement causes the device 76 to be placed across Line 1 and Line 2 to be operated thereby.

When the aperture 60, program sheet 58 subsequently comes into register with the passage 28, the vacuum condition in the closure 64 is broken and air enters switch 44 permitting the natural resiliency of the diaphragms 62, 3 to return to their natural position. The contacts 65, 6c are disengaged thereby deenergizing the device 79. Therefore, it can be seen that the switch construction operates in a relatively simple manner to make and break electrical connections.

Another embodiment of the present invention is illustrated in FIGURE 1, as switch 46, wherein like parts are indicated by like reference numerals and the general and detailed description of the like parts of the switch construction apply to the switches 42 and 44. A third con tact 72 mounted on divider 73 allows the switch to be operated in two directions. This embodiment will be hereinafter described in full.

Referring now to FIGURE 4 and where one embodiment of the present invention is illustrated thereon, the switch structure 89 consists of a housing 81 and electrical contacts 32, 83, mounted on each side of the housing in juxtaposition, and a means for flexing the housing.

The housing 81 composed of a pair of identically shaped circular disc diaphragms 84, 85 are joined at their periphery to form an airtight closure. The particular shape of the diaphragms is not limited to the circular form as illustrated in FIGURE 4 and 5, but rather extend to any form of diaphragm which may flex.

Materials suitable for the diaphragms are preferably of plastic varieties such as polycarbonate, which is preferred since it has self extinguishing and high temperature properties. Other plastics which may also be used for the diaphragms are polyethylene, polypropylene, fabric reinforced with polyester resin, acctal resin, et cetera. Sheet metals may also be used for the diaphragms but the contacts must be insulated from the diaphragm or an insulation must be inserted between the two halves of the diaphragms to prevent short circuits.

Plastic diaphragms must be attached at their periphery by some suitable joining process such as heat sealing, solvent welding or the like. Metal diaphragms may be attached by plastic cements, welding, soldering, brazing and the like. In any event, the diaphragms must be joined together to form an airtight seal.

Referring now in particular to FIGURE 5, the contact 83 illustrated is composed of two materials, namely, a base 86 and a contact or head portion 87. It is conventional to use material such as silver or good electrical conductors for the head portion and a cheaper metal for the base to decrease the cost of the unit. The contact has a nose portion that extends through the diaphragm 85 which is cr'unped over or swaged into intimate contact with the lug or electrical terminal 88. Sufficient pressure must be placed upon the swaging operation in order to make the contact and diaphragm airtight. Disc 4 89 is interposed between the diaphragm and the lug or terminal 88 for stiffening the assembly and preventing local stresses.

The second contact 82 is positioned opposite the first contact 83 and has a similar silver or other good elec trical conductor attached to the base. The leg of the second contact 82 extends through the diaphragm 34 and has a lug or terminal 88 mounted thereon with a disc 89 interposed between the terminal 88 and the diaphragm 84. A portion of the contact leg 90 is swaged or turned over the terminal for mechanical fastening purposes.

A means for flexing the diaphragm must be provided so that the contacts can engage each other and pass electrical current from one terminal to another. One manner of flexing the diaphragms is to provide a vent for evacuating the air between the diaphr'agms, and in the present embodiment this vent is provided by having a passageway 2 coaxially positioned on the contact leg 90 interconnected with the transverse opening 91. A vacuurn line can be connected to the contact leg 92 to thereby evacuate the switch, flex the diaphragms, and cause the contacts to engage. The position of this vacuum vent is only illustrative and any vent may be positioned on any portion of the switch for evacuation purposes.

FIGURE 6 illustrates another embodiment of the prescnt invention in which a single pole, double throw switch is illustrated. This embodiment has the same arrange ment of the contacts on the two diaphragms as illustarted in FIGURES 4 and 5.

An additional diaphragm 93 or support means is interposed between the two diaphragms 84, 85, and has a contact 94 mounted thereon in a conventional manner. The middle support or diaphragm 93 has a Wire 95, or printed circuit, or other conductive means sandwiched or dis posed in the interior of the diaphragm 93 and attached to the contact 94 and terminal 96. The diaphragms may be flexed individually by applying a vacuum at the contact'90, 9t) separately, or a vacuum may be applied to both diaphragms concurrently to make the contacts at all three terminals simultaneously. The central supported diaphragm may be either solid or flexible, depending upon the arrangement and the size of the switch.

Referring now to FIGURES 7 and 8,- there is illustrated two embodiments of the present invention which pro vide contact elements having a wiping action. The switch illustrated in FIGURE 7 has contacts 101, 1632 po sitioned opposite each other and attached in a manner illustrated and described with relation to the switch in FIGURES 4 and 5. The diaphragms 193, 1nd are flexible in nature and attached at the periphery, however, the central portion 105, 166 respectively are inclined with relation to the remainder of the diaphragm, thereby canting each contact.

As the switch, illustrated in FIGURE 7 is actuated by applying a vacuum to the contact passageway N7, the diaphragms m3, 104 flex, causing the contacts N1, 162, to engage each other. As the contacts are moved into greater engagement, there is a slight lateral movement of the contacts which prevents a weld from forming and tends to clean the contact faces of any material caused by the arcing of the contacts.

Referring now to FIGURE 8, the switch 108 is another embodiment of the switch illustrated in FIGURE 7 and has a similar Wiping action effected by the contacts. In this embodiment, the entire switch 1438 is very similar to the switch 80 illustrated in FIGURES 4 and 5. The con! tacts 82, 83, have angular faces 169, 11%, respectively such that as the diaphragms are flexed toward each other, the contacts will have a slight lateral movement thereby giving a wiping action similar to the operation described in relation to the switch 100 illustrated in FIGURE 7.

The embodiments illustrated in FIGURES 9, 10, and 11 of the present invention relate generally to normally closed contacts which are opened upon an operation. of a diaphragm flexing means.

Referring now to FIGURE 9, the switch 111 comprises a pair of diaphragms '84, fixedly attached to each other at their periphery and having a contact, and terminal arrangement similar to that illustrated in FIGURE 5. A looped shaped arm 112 is fixedly attached to the diaphragm 84 by a rivet 113 passing through the stifiner 89 and terminal 88. This arm 112 has a contact 114 mounted at its extremity which is in engagement with the contact 82. Arm 112 also has a curved portion 115 which is in spaced relation with the disc 89 and acts to pivot the contacts 82, 114, out of engagement upon movement of the diaphragms 84, 85 toward each other. Arm 112 is prevented from short circuiting the switch 111 since its curved portion 115 contacts an insulator disc 89 that prevents such short circuiting.

In operation, it may be seen that as the diaphragms 84, 85 are fiexed toward each other, by delivering a vacuum to the interior of the switch 111, such that the curved portion 115 of arm 112 contacts the disc 89, tending to pivot the contact 114 from contact 82. Further movement of the diaphragms 84, 85 toward each other, moves the contacts 82, 114 further out of engage ment.

The embodiment illustrated in FIGURE 10 is somewhat similar to the embodiment illustrated in FIGURE 9. Switch has a pair of diaphragms 84, 85 attached at their periphery and having a contact 82 passing through pivot bar 121, diaphragm 85, stiffener disc 89, and terminal 88.

A U-shaped spring arm 122 is attached to diaphragm 84 by a rivet 123 passing therethrough and stiffener disc 89 and terminal 88 positioned on the opposite side of the diaphragm. Contact 124 mounted at the end of the spring arm 122 is normally in engagement with the contact 82. An upstanding post 125 from the pivot bar 121 is in spaced relation with the spring arm 122 and operates in a similar manner to the switch construction of FIGURE 7. Movement, of the diaphragms 84, 85 toward each other, forces the arm 122 to contact and pivot on post 125 to thereby disengage contacts 82 and 124.

Another embodiment, of the present invention, relating to a normally closed switch is illustrated in FIG- URE 9. Diaphragms 84, 85 are attached at their periphery and have a contact 82 passing through insulated discs 89 and terminal 88.

Attached to the diaphragm 84 by rivet 133 are a terminal 88, insulated disc 89, a rigid backing plate 131, and a looped shaped spring arm 132. Arm 132 has a depressed portion 134 in its central area having a contact 135 mounted thereon which is in engagement with contact 82. This depressed portion 134 leaves downwardly, projecting curved portions 136, 137 which are in spaced relation with the insulated disc 89. Therefore it may be seen that movement of the diaphragms 84, 85 toward each other, forces the curved portions 136, 137 of the spring arm 132 to engage the disc 89 thereby tending to force the contacts 135, 82 out of the engagement. The rigid backing plate 131 constantly forces the spring arm 132 downwardly, tending to keep its conformed shape and prevents deflection of the upper portion of the spring arm 132 during the switch actuation.

Referring now to FIGURES 12, 13, 14 and 15, there are illustrated several more embodiments of the present invention relating generally to normally closed switch constructions.

The switch 140 illustrated in FIGURE 12 comprises a pair of diaphragms 84, 85 sealed at their periphery and having two contacts 141, 142 normally in the closed position. Terminal 88, insulated disc 89, and a contact arm 144 positioned within the switch are held thereto by a rivet 145 being staked on both sides of the diaphragm 85.

Nipple 146 having an outwardly extending flange 147 retains the terminal 88 and insulated disc 89, contact 6. arm 143, and overtravel stop 148 against the diaphragm 84. Nipple 146 has a passageway therethrough for communication of a vacuum into the interior of the switch for flexing the diaphragm toward each other. Contact arm 143 has a downwardly extending shoulder 149 which is electrically contacting the lug or terminal 88. Electrical contact 141 mounted at the extremity of the arm 143 is in electrical engagement with contact 142.

In operation, the diaphragms 84, 85 are flexed toward each other until the contacts 141, 142 are disengaged. The overtravel stop 148 prevents the contact 141 from engaging the nipple 146 and short circuiting the switch.

Referring now to FIGURE 13, another embodiment is illustrated of the present invention as applied to normally closed switch 150. This embodiment has a similarity to the embodiment illustrated in FIGURE 12 but has an additional terminal on one diaphragm to provide a single pole double throw arrangement.

The switch 150 has a pair of diaphragms 84, 85 sealed at their periphery and a contact arm 151 and terminal 152 being mounted on diaphragm 84 by a hollow nipple 153 having a lateral flange 154 contacting terminal 152 and a staked portion engaging the contact arm 151. The passageway 155 through the nipple 153 provides an access port for evacuating the interior of the switch. The contact 156 is suitably mounted on the extremity of the contact arm 151.

On diaphragm 85, there is mounted a pair of terminals 151, 158 separated by an insulating disc 159 and a contact arm 160 in electrical engagement with the lower terminal 158. An elongated contact 161 is staked on the upper terminal 157 and extends through an insulating nipple 162 terminating in a head portion 163 in juxtaposition and spaced relation with the contact 164 mounted on arm 151. Contact arm 160 has a shoulder 165 which is in engagement with the terminal 158 and has thereon an electrical contact 156 which is in engagement with the contact 164, therefore forming electrical continuity between terminal 152 and terminal 158.

In operation, evacuation of the central portion of the switch causes the contacts 156 and 164 to disengage and thereafter contact 164 engages contact head 163 to provide electrical connection between terminal 152 and terminal 157.

Referring now to FIGURES 14 and 15, another embodiment of the present invention is adapted to a double pole-double throw switch in which two terminals are positioned on each of the diaphragms.

A pair of diaphragrns 171, 172 are sealed at their periphery and each diaphragm has two contact arms respectively which are individually in contact with their respective terminals. Specifically, on diaphragm 171 there is mounted a terminal 173 having an elongated contact 174 staked at both sides and extending through an insulated nipple 175 and engaging a contact arm 176 having contact 176a mounted thereon. An insulating disc 177 separates terminal 173 from terminal 178. A second contact arm 179 has a shoulder 180 which is in electrical contact with terminal 178. The second insulating disc 181 separates the terminal 178 from the diaphragm 171. Contact 182 extends through the extremities of the contact arm 183 so that contact can be made on either side of the arm. Insulated disc 186 separates arm 176 from arm 179.

A similar arrangement having two contact arms 183, in electrical contact with two terminals 173a, 178a respectively, is mounted on diaphragm 172.

The hollow nipple 187 has a peripheral flange 188 supporting the terminal 173, extends through the diaphragm 172 and is staked on the contact arm 185. An insulating tubing 189 prevent-s contact between the nipple 187 and contact arm 183. Terminal 178 is insulated by a pair of insulating discs 177, 181 positioned on opposite sides thereof and is in engagement with the shoulder 190 of the contact arm 183. The contact arms 183, 185 both have contacts which extend therethrough and are able to make electrical engagement on either side thereof.

In operation, as illustrated terminal 173 is electrically connected with terminal 173a. Once the central portion of the switch 170 is evacuated, the diaphragms 171, 172 flex toward each other until contact 191 engages contact 192. In this second position, terminal 178 is in electrical contact with terminal 178a.

From the various embodiments with this present invention, which are shown and described, it may be seen that a plurality of terminals may be placed on either side of the diaphragms with a multitude of switching arrangements positioned within the switch construction, which will all be within the spirit of the invention. It is also possible to construct the switch with the contacts normally closed and operate the switch by using a pressure source. These embodiments are only illustrative and the various modifications of the switch arrangements and terminal arrangements may be made without departing from the scope and the spirit of this invention as defined in the appended claims.

We claim:

1. A switch comprising: a pair of disc shaped circular diaphragms attached to each other at their periphery to form a hollow housing, a first contact attached to one of said diaphragms, a second contact attached to the other of said diaphragms such that it is positioned opposite to said first contact, said contacts extending within said housing and having contact faces facing each other, a nipple attached to one of said contacts, said nipple and contact having a passageway therethrough and terminating in spaced relation with said contact face and within said closed housing whereby source of pressure may be attached to said nipple to evacuate the housing and flex the diaphragms toward each other and vary the spacial relation of the contacts with relation to each other.

2. A switch comprising: a pair of thin cup shaped circular diaphragms attached to each other at their periphery to form a hollow housing, a first contact attached to one of said diaphragms, a second contact attached to the other of said diaphragms such that it is positioned opposite to said first contact, said contacts extending within said housing, said contacts each having a face portion, said contacts positioned within the housing such that their faces are at an angle less than 180 to the diaphragms, and a means for evacuating said housing for flexing the diaphragrns to alter the position of the contacts in relation of each other whereby the engagement or disengagement of the switch gives a wiping contact, said means for evacuating said housing including a passageway through one of said contacts, terminating in spaced relation with said contact face thereof and within said hollow housing.

3. A switch comprising: a pair of flexible thin cupshaped diaphragms attached to each other to form a hollow closed housing, said diaphragrns each having an angular portion thereon making an angle of less than 180 relative to the respective diaphragm, a first contact attached to one of said diaphragms Within said angular portion, a second contact attached to the other of said diaphragms such that it is positioned opposite said first contact and positioned within said angular portion, said contacts each having a face portion, said contacts mounted on said diaphragms angular portions so that said contacts are positioned at an angle relative to the remainder of the diaphragms whereby the engagement of the contacts gives a wiping action, and a means for evacuating said housing for flexing the diaphragms to alter the position of the contacts in relation to each other, said means for evacuating said housing including a passageway through one of said contacts, terminating in spaced relation with said contact face thereof and within said hollow housing.

4. A diaphragm switch comprising: a pair of flexible: thin cup-shaped diaphragms attached to each other to form a hollow closed housing, a first electrical contact attached to one of said diaphragms, a second contact attached to the other of said diaphragms such that it is positioned opposite to said first contact, said contacts hav-- ing a face portion positioned at an angle less than relative to the diaphragm, whereby the engagement of the: contacts gives a wiping action, and a means for evacuat-- ing said housing for flexing the diaphragrns to alter the: position of the contacts in relation to each other, said means for evacuating said housing including a passageway through one of said contacts, terminating in spaced relation with said contact face thereof and within said hollow housing.

5'. A switch comprising:

a pair of non-metallic flexible diaphragrns attached at their peripheries forming a hollow housing,

a pair of contacts mounted one each on said diaphragms and having faces thereon which are engageable with each other,

one of each contacts having a passage therethrough, and terminating in spaced relation with contact face and within said closed housing,

whereby upon engagement of said contacts by applying a vacuum to said contact passageway that said passageway is not covered when said contact face is en gaged.

6. A switch as defined in claim 5 in which said passageway is in the shape of a T.

7. A switch comprising:

a pair of non netallic flexible diaphragms attached at their peripheries and forming a hollow housing,

a pair of contacts mounted one each on said diaphragms and having faces thereon which are engageable with each other,

one of said contacts having a passage thercthrough and terminating in spaced relation with said contact face and within said closed housing,

a nipple mounted to said contact having a passageway therethrough and said passageway passing through said nipple,

a pair of electrical terminals attached one each to said contacts and extending exteriorly of said closed houss,

whereby upon engagement of said contacts by the application of a vacuum to said nipple passageway, said contact faces may engage without closing off tie vacuum passage, and electrical energy may pass from one terminal to the other.

References Cited by the Examiner UNITED STATES PATENTS 1,684,530 9/1928 Bast 200-83 2,143,103 1/1939 Cox 200-83 2,367,441 1/1945 Schwinn 20061.12 2,496,229 1/1950 Parkhurst 200166 2,501,867 3/1950 Gleisen 200--83 2,762,895 9/1956 Throw 20083 X 2,798,130 7/1957 Cox 200-83 2,824,183 2/1958 Marasco et al 200168 3,009,032 11/1961 Friend et al. 20083 3,018,353 1/1962 Mitchell 200166 BERNARD A. GILHEANY, Primary Examiner. 

1. A SWITCH COMPRISING: A PAIR OF DISC SHAPED CIRCULAR DIAPHRAGMS ATTACHED TO EACH OTHER AT THEIR PERIPHERY TO FORM A HOLLOW HOUSING, A FIRST CONTACT ATTACHED TO ONE OF SAID DIAPHRAGMS, A SECOND CONTACT ATTACHED TO THE OTHER OF SAID DIAPHRAGMS SUCH THAT IT IS POSITIONED OPPOSITE TO SAID FIRST CONTACT, SAID CONTACTS EXTENDING WITHIN SAID HOUSING AND HAVING CONTACT FACES FACING EACH OTHER, A NIPPLE ATTACHED TO ONE OF SAID CONTACTS, SAID NIPPLE AND CONTACT HAVING A PASSAGEWAY THERETHROUGH AND TERMINATING IN SPACED RELATION WITH SAID CONTACT FACE AND WITHIN SAID CLOSED HOUSING WHEREBY SOURCE OF PRESSURE MAY BE ATTCHED TO SAID NIPPLE TO EVACUATE THE HOUSING AND FLEX THE DIAPHRAGMS TOWARD EACH OTHER AND VARY THE SPACIAL RELATION OF THE CONTACTS WITH RELATION TO EACH OTHER. 